Radio signaling system



P 6, 1930. E. F. w. ALEXANDERSON 5,801 RADIO SIGNALING sYsxml Filed Nov. 15, 1927 4 Sheets-Shet 1 Inventor: Ernst F W Alexander-son, bu W His Atco'w'neg.

Sept. 16, 1930. E. F. w. ALEXANDERSON 1,775,801

1510 SIGNALING SYSTEM Filed Nov. 15. 1927 4 Sheets-Sheet 2 Inventor: a Ernst FW Adexondefsov bg fl His Abto'r' nejg.

p 6, 1930; E. F. w. ALEXANDERSON ,8

RADIO sieuALInG SYSTEM Fild Nov.-15, 1927 4 Sheets-Sheet s Inventor': Ernst E'WAlexomdevson,

b M His Attorney.

p 6, 1930. E. F. w. ALEXANDERSON ,8

RADIO SIGNALING SYSTEM Filed Nov. 15. 1927 4 Sheets-Sheet 4 Ihve nto-r: Ernst F W Alexomdevso'n u M His Attorneg.

Patented Sept. 16, 1930 UNITED snares PATENT OFFICE ERNST F. W. ALEXANDERSON, OF SCHENECTADY, NEW YORK, .ASSIGNOR T GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK A RADIO SIGNALING SYSTEM Application fi led November 15, 1927. Serial No. 233,509.

'My invention relates to radio signaling systems and more particularly to radio signaling systemswhich are adapted for opera tion on short waves. Ithas for'its purpose to provide directive antenna systemsfor use in such systems which are easy to construct and maintain and which-combinev high radiating capacity and sharp directive properties with economy in construction and main-.

tenance. A still further purpose of my invention is to provide an antenna system which may be constructed without the use of artificial inductance or capacityor tuning of any nature and which is therefore pecu- 5 liarly capable of operationsimultaneously on a number of different wave lengths. This latter characteristic of antennae embodying my invention is of particular importance in connectionwith the problem of fading as well as in eliminating distortion resulting from fading. i v

Various theories have been advanced in the past to account for the erratic reception of radio waves and for the phenomenon known as fading. Among these isithe theory of the Heavyside-Kennellylayer which theoreti cally comprises a conducting medium upon which waves travel to a. remote point and from which waves are reflected and refracted so to the vicinity of the receiver. Experiments with radio transmission appear to indicate that this layer is not a smoothsurfacebut instead one which is not unlike that of the surface of the sea in various states of agitation. If a radio beam is radiated to this surface it may be reflected back to the earthin the vicinity ofthe receiver or to other vicinities dependent upon the condition of the layer. Consequently conditions of alternate receptlon and non-receptlon, or fading, occur at the recelver.

Accordingly one of the purposes of my invention is to provide an antenna whichin addltlon to possessing sharp directive properties and the capacity to radiate large quantities of energy is also capable of operation at a plurality of wave lengths. Since the waves of different wave lengths may be affected differently by the fading phenomena of the ether or by different conditions of the be expected. Such an antennamay more properly be termed a wave projector as contrasted with the usual beam antenna ofthe prior art which operates only on a single wave. t

More particularly my wave projecting antenna comprises av plurality of half wave length sections all of which operate in unison and in phase to project either a single wave or a plurality of waves in a given di:

rection. These sections my be arranged in a plurality of lines and in adjacent space relation in each line, thereby securing large radiating capacity and high directive properties of the antenna as a whole. The diflerent half Wave length sections of each line may be interconnected and arranged in a manner to be described such that all 'of'the sections operate in phase and this without the use of condensers, inductance or tuning means of any kind which interfere with operation at a plurality of frequencies. 7 Y

The novel features which I believe to be characteristic of my invention will be set forth with particularity in the appended claims. My invention itself, however, both as to its organization and method ,of operation may best be understood by reference to. the following description taken in connection with the accompanying drawing in which Figs. 1 to12 illustrate diagrammati-. cally as many difierent embodiments of my invention. .a

In the drawings the heavy lines have been employed to indicate the conducting members ofrthe antenna, whereas the light lines 1 and 2, each of these members comprising a plurality of series connected alternately arranged sections. These sections in the case shown are arranged in a zig zag formation and extend alternately in the horizontal and vertical planes. Thus, for example, the conducting member 2 is composed of a set of horizontal sections a, Z), and c, which are alternately arranged along the length of the antenna, and a set of sections (Z, c intermediate said alternate sections, which are in a vertical plane. Conductor 1, which is similarly formed of sections a, b, 0, d, e, is juxtaposed upon the conductor 1 in a manner such that two parallel continuous lines are formed and the pairs of sections (Z, d and e, a form opposite sides of a parallelogram between these lines. The upper of these lines comprises sections a, b and c and the lower line comprises the sections a. b and 0., these sections being arranged in adjacent space relation in each line, and each constituting a half wave length oscillating unit. The sections 6 and Z) are interrupted at the midpoint theretif and the two conductors are connected together at this point by means of feed lines 3, at the midpoint of which are connected additional feed lines extending to the high frequency apparatus 4:, which may comprise a transmitter or receiver. The feed lines 3 extending between the two lines may have a length equal to a half wave length or an integral multiple thereof as desired. Ihe arrangement of the feed lines is such that the high frequency apparatus 4 is electrically equidistant from the midpoint of both of the conducting members 1 and 2. The conductingmembers 1 and 2 are suitably supported from appropriate towers 5 and 6 by means of cables 7 and are appropriately insulated from each other by means of suitable insulators 9, which in each of the drawings are represented as circular disks. The high frequency apparatus 4. may be operable to sup ply to, or to receive from. the antenna currents of one or more frequencies. If currents of a single frequency be employed. then the length of each of the sections of the an tenna will be equal to one-half of a wave length. corresponding to the frequency used, whereas, if more than one frequency is used, these sections will have a length equal to onehalf of the average wave length of the waves employed. As thus arranged it will be seen that all the sections which comprise the parallel lines a, 7). 0 and a, b, 0 will be energized in phase. whereas the currents in the coextensive mcmbers (1, (1 and e, e. which form oppositely disposed connecting links between the parallel lines, will flow in opposite directions as is indicated by the arrows with the result that the effect of these members will be neutralized. It will thus be seen that all of the horizontal members of the antenna will be energized in phase, and thereby cooperate to project, or to respond to, horizontally polarized waves propagated in a direction at right angles to the plane of the antenna, whereas the vertical members because of their opposed phase relations will have substantially no effect.

In Fig. 2 I have shown a further development of my invention which comprises two groups 10 and 11 of conductors arranged in the manner set forth in connection with Fig. 1. These groups are arranged to form. two parallel lines in a vertical plane extending between the towers 5 and 6, each of these lines comprising six half wave length oscillating sections, all of which may be energized in phase by means of a transmitting equipment 4, which is connected through lines of equal length to the midpoint of the feeder conductor 3 of the two groups of conductors. This antenna will project a wave of a similar nature to that projected by the antenna shown in Fig. 1, but due to its great er length will have sharper directive and greater radiating properties than that of the former figure.

The directivity and radiating properties of the antenna will be still further increased by an arrangement of conductors such as that shown in Fig. 3. In this figure four groups of members 12, 13. 14 and 15, each of them being constructed in a manner illustrated in connection with Fig. 1, are suspended be tween towers 5 and 6. The groups 12, 1.3 and 1 k, 15 are suspended in vertical planes between spreaders 16 and 17 which are attached to the supporting mast 5 and 6, the length of these spreaders and consequently the distance between the two vertical planes comprising the groups 12, 13 and 14, 15 being equal to onehalf of a wave length. In this case only the groups 14: and 15 are represented as being energized by means of the transmitter 4. the groups 12 and 13 serving as reflectors of the radiated waves. 7'

Fig. 4: represents an antenna of the type shown in Fig. 1 but which is suspended between towers 5 and 6 in a manner such that the direction of propagation of the radiated waves may be varied as desired. The parallel lines of the antenna which are comprised of the alternate sections of the con ducting members 1 and 2 are suspended between spreaders 18 and 19, which spreaders are suitably attached to the supports 5 and 6. These spreaders 18 and 19 are suspended in a manner such that they may be rotated in a vertical plane extending crosswise of the antenna. Opposite ends of the spreaders 18 and 19 are attached by means of ropes 20 and 21 respectively to stakes 22 which may be set in the ground at suitable distances from the base of the supports 5 and 6. By means of these ropes the angle of propagation of the radiated waves over the horizon may be adjusted. Thus, for example,

by making the ropes 20 and 21 of, equal length and by; setting the stakes 22 in the] ground at equal. distances from the base of the support 5 the antenna will be suspended.

in the horizontal plane, thereby projecting horizontally polarized waves vertically up- Ward. If the ropes 21 be lengthened and the ropes 20 shortened and the stakes 22 suitably adjusted, the antenna may besuspended in a vertical plane whereby horizontally polarized waves may be projected parallel to the surface ofitheearth. Suitable intermediate angles as'desired between the direction of propagation ofthe-radiated waves and the surfaceof the earth mayaccordingly be ob;

tained.

v Fig. 5 shows an antenna of the type represented in Fig. 2 similarly suspended 'so'as to make the directionjof propagation of the radiated waves over the horizon'adjustable.

, Suitable means of the natureset'out in Figs.

4 and 5 may also be employed in connection with an antenna. having a group arrangement such as that shown in Fig. 3. i I

Fig. 6 represents a different manner of supportingan antenna of the type-shown in either Fig. -2 or Fig. 5. In this figure two groups of conductors are suspended from the topaof' a tower 23 in end to end relation obliquely towardthe ground, the lower ends of eachlof the lines ofthe radiating conductors being supported by means ofsuitable stakes '24 whichmav be set inthe earth. As thus constructed this antenna- Will radiate a wave having a direction of propagation: at right angles'to the plane of the antenna and the plane of polarization determined. by the angle betweenthe plane .of the surface of the earth.. The direction of propagation of this antenna may likewise be varied, over the horizon by movingthe stakes 24 to or from the base ofthe support 23. Thus, for'example, the angle be-- tween the direction of propagation and the I surface of the earth may be diminished as desired by so adjusting the stakes 24 that the plane of the antenna willfall into a plane determinedby the .dotted lines 25 or it may be increasedby adjusting the stakes in the opposite direction.

Fig. 7 represents a further embodiment of my invention in which the two conducting members. 1 and 2 are comprised of series connected alternately arranged sectionswhich;

may be arranged in a general zig zag'or staircase formation, the alternating sections of each conductor extending in opposite direction from the intermediate sections thereof. Thus, for example, the conductor 1 com-' prises sections 9, h, t', j and 7c, the set of" sections g, horizontal sections it and 7' being arranged in the vertical plane; The conductor 2 is similarly formed of sections 9,

and I: being arranged in the the antenna and plane and the intermediate set of tion .in.;each:line. Themid-sections of each 4. This antennais adapted to be. supported .by meansof afsuspension member 26 which extends from thew-top of the toWer27 ob-.

liquely toward the earth. *This form of. antenna is of a type disclosed and claimed n a copending applicationof Samuel Nixdorf,

and f the sections. and k. and g and of the conductors'lare connected by means:

ofthe feeders 3 inna mannenalready set forth in connection with;Figs.;1 and :2 and :the midpoints of these feeders are similarly connected .to, the high" frequency apparatus filed Nov; 15,1927, Serial. No.,233,&91, and; which is; assigned'tothe same =assignee ,as

my. present application: .It; has certain ad vantages in its physical. construction as Well as in its methodof operation which are. fully set forth. inthe .copending application.

When supplied. with high: frequency cur rents having a wave length equal to twice the length of-=the equal sections of the conductor,

. currents will flow ineach 'ofthe condu'ctorsin a directionindicated by the arrows. I It will thus be seen; that all of thezsectio'ns which are;

zontal and the. vertical sections; Thusin this antenna. both the vertical and the horizontal members produce radiation and thecombined effect, of the horizontal. and vertical-.m'embers is topro-ject a Wave in a directionatright an?- arranged in parallel relation-are energized in phase and that this is true withyboth the horilUO gles. to..the planefof-ithe antenna. having a 5 as is indicatedbythe arrow 28.

F g. 8 representsa further embodiment of i my invention in which two groups ofconductors,.such that shown; in are sus-- plane 'of polarization "at {15 degrees.- upward 1 pendedinj en'd to endrelation: and in a ;horizontal plane betweensupportsn and 6. These groups are insulated ffron each other at the point .31 .and'are energized byvmeans of icons ductorsf 32 and 33 of equal length which es} tend from the midpoint of the feeder section 3 to the high frequency apparatus 4. thus arranged this antenna will. radiateawavepin a vertical directioutvliicli has'a horizontal plane of polarizationf Suclian antenna will {direction of. aircraft:

Figs. 9 and 10 represent further develop 'ments of the form of my invention representhave particular utility in connection wit-lithe ed in Fig.7. Fig.9, representsasingle group of conductors whlch are suspended in a vertical plane betweenthe masts 5-and.'6,each of j the sectionsofeach conducting memberlbeing. disposed.at'odegreestothe horizontal. F ig; fl,

shows two groups of conductors similarly arranged extending in end to end relation in j rents through the conductors 32 and 38 which are of equal length and extend from the high frequency apparatus 4 to the midpoint of the feeder sections 3. These antennae as represented by Figs 9 and 10 will transmit vertically polarized waves having a direction of propagation at right angles to the'plane oi the antenna.

Figs. 11 and 12 represent antennae of the type shown in Figs. 1 and 9 respectively with the except-ion that the spacing between the upper and lower portions of the antennae is greater. In each of these figures the len th of the feeder conductors 3 is equal to a Full wave length with the result that the currents in the lower portion are reversed in direction with respect to that shown in the other figures. These antenae will project or respond to waves propagated at a right angle to the plane of the antenna but thirty degrees upward over the horizon. The angle may be reduced to fifteen degrees by increasing the distance to two wave lengths. In the form shown in Fig. 12 the distance between the upper and lower portions is arbitrary.

It will be seen that, by an arrangement of conductors such as that described, any. desirable length of antenna may be had, all of the half wave length sections of each of the parallel lines of the antenna cooperating in phase and being arranged in adjacent space relation. The fact that the various sections are energized in phase greatly increases the signal strength which may be had at a remote point with a given energy input to the antenna. Tests with an antenna of theftype shown in Fig. 1 have indicated that far less energy is required to produce a certain signal strength at a given point than would be required by the usual half wave length horizontal doublet. The directive properties of the antenna are likewise increased both in the horizontal and vertical planes. This characteristic of the antenna is enhanced by the fact that the individual oscillating units, or sections, are arranged in adjacent space relation in each line. a V 7 While in each of the figures shown the conductors comprising the antenna each include an odd number ofsections it will be understood that an even number may be employed as well. Likewise while in each case the antenna is represented as being fed at a midpoint of a mid-section any suitable manner of feeding well-known in the art maybe employed While the conductors may be of any suitable length it is desirable that the length should notbe so great that the difference between theenergizationo'f the more remote sec sections will be substantially equally energized. Likewise the angle between adjacent sections of any conductor while preferably about ninety degrees may be any substantial angle.

While I have shown and described certain embodiments of my invention it will of course be understood that I do not wish to'be limited thereto since many further modifications of the arrangements shown and of the instru mentalities employed may be made without departing from the spirit and scope of my in vention as set forth in the appended claims.

lVhat I claim as new and desire to secure by Letters Patent of the United States is:

1. In combination, an antenna comprising a conductor including a number of substantially equal series connected sections, certain of said sections being alternately'arranged along the length of said conductor and in parallel relation and certain other of said sections being arranged intermediate said alternate sections and at an angle thereto, a second similar conductor arranged in proximity to said first conductor to form parallel lines including sections of both conductors, high frequency apparatus adapted for operation at a wave length equal to approximately twice the length of said substantially equal sections 7 and connections from the mid-point of each of said conductors to said high frequency apparatus.

2. An antenna comprising a conductor including a number of substantiallyequal series connected sections, certain of'said sections being alternately arranged along the length of said antenna and in horizontal parallel relation and certain other sections being arranged intermediate said alternate sections and at an angle thereto, and a second similar conductor arranged in such juxtaposition with said first conductor that said' alternately arranged sections of both conductors form continuous parallel horizontal lines spaced apart by at least one half of a wave length of the wave on which said antenna operates and certain intermediate sections of both conductors are coextensive with each other.

3. In combination, an antenna. comprising and at an angle thereto, said alternately arranged sections of all of the conductors forming parallel lines and said intermediate sections extending between saidlines, high frequency apparatus and lines of equal electrical length extending from said high frequency apparatus to a point intermediate each of said pairs and from said point to each conductor of said pairs whereby parallel sections of all of said conductors produce cooperative effects. V

4. An antenna adapted for operation on horizontally polarized waves comprising a' plurality of sections, said sections being ar-. ranged in horizontal parallel rows spaced apart by a clistanceof one-half of a wave length, each row comprising a plurality of being supplied to said equal sections arranged inend to end relation,'high frequency apparatus conne'cted'to the mid-point of the middle sections of each of said rows, and means for so coordinating all of said sections that they carry currents in phase when high frequency oscillations are impressed upon said antenna.

5. A system for radiating horizontally polarized waves comprisingan antenna hav- 1ng a plural ty of equal sections, said sections being arranged in horizontal rows in V a substantially vertical plane and spacedv apart in said plane by a'distance of one half of a wave length of the wave on which said antenna. operates, means for supplying high frequency oscillations to saidantenna having a Wave length equal to twice the length of said equal sections, means for so coordinating all of said sections that they carry currents in phase, and a second antenna comprising sections similarly arranged in a vertical plane onthe side of said first vertical plane opposite the direction in which waves are to be propagated, energy second antenna entirely through the inherentcoupling between said antenn r 6. An antenna adapted for operation on horizontally polarized waves, comprising a plurality of equal sections arranged in horizontal rows spaced apart byone-half of a wave length of the wave on which said antenna operates, said rows being arranged in a. substantially vertical plane, and each of said 'rows including at least three of said equal sections, high. frequency apparatus connected to the mid-point of the middle section of each row, and means for so coordinating all of said sections that they carry currents in phase whenhighfrequency oscillations are impressed on said antenna.

In witness whereof, I have hereunto set my hand this 14th day of November, 1927. V

ERNST F. W. ALEXANDERSON. 

